Sleeve, particularly a rod sleeve

ABSTRACT

A rod sleeve, at least comprising a core having a core hub that has two faces and a core pin, which extends in the direction of a longitudinal axis Y. This core pin projects over both faces of the core hub while forming two connecting journals. The sleeve also comprises an outer sleeve and an elastic layer located between the core hub and the outer sleeve. The core hub and the core pin form a one-piece core system that is in the form of two parts with regard to a normal axis X to the longitudinal axis Y. Both core halves are assembled with interference fit via an insertion-slot system. The core hub between its two faces undergoes a tapering with an angle change α, whereby the respective contact surfaces of the core hub and of the outer sleeve extend in a manner that essentially corresponds to the elastic layer. The outer sleeve and the elastic layer are provided in two parts with regard to the normal axis X to the longitudinal Y. Both sleeve halves are assembled with interference fit by means of an insertion-slot system, whereas both elastic layer halves are placed at a distance L 1  from one another.

The invention relates to a sleeve, particularly a rod sleeve, consisting at least of:

-   -   a core made of metal or plastic (e.g. on the basis of         polyphenylene ether), comprising a core hub that has two faces         with a first and a second diameter, and a core pin which extends         in the direction of the longitudinal axis, which projects over         both faces of the core hub while forming two connecting         journals;     -   an outer sleeve that also consists of metal or plastic; as well         as     -   an elastic layer that is arranged between the core hub and the         outer sleeve.

Sleeves of this type, whereby reference is particularly made to the references DE 30 04 194 A1, DE 42 08 448 C2, and DE 199 13 777 C1, are predominantly used in rail vehicle technology, which will be explained in greater detail in the following.

A significant aspect is the guidance of the wheel set of a rail vehicle by means of an elastic, play-free joint, linearly in the three directions of space, and torsionally, i.e. cardanically around the point of rotation of a guide arm, which is attached to the frame of the rail vehicle by means of a guide element (rod sleeve). In this connection, the longitudinal axis and height axis of the vehicle lie in the radial direction of the guide element, while the crosswise axis of the vehicle lies in the axial direction of the guide element.

With the background of this technology, the following requirements must be met:

-   a) One significant requirement is great rigidity in the radial and     the axial direction. The required ratio of radial to axial rigidity     is approximately 1:1 to 3:1. At the same time, a low torsion     rigidity with simultaneous great cardanic rigidity is desirable. The     ratio of cardanic rigidity to torsion rigidity should usually be     approximately 10:1.     -   In the case of a conventional cylindrical elastomer sleeve,         however, the ratio of radial to axial rigidity is too great, at         approximately 5:1 to 10:1.     -   In the case of a spherical elastomer ball joint, the ratio of         cardanic to torsion rigidity is too low, at approximately 3:1 to         5:1.     -   The aforementioned requirements can therefore not be met         simultaneously by either one of the two conventional design         principles. -   b) Another requirement is that if needed, a mechanical fixed stop     that acts in the radial direction can be integrated into the     component.     -   This requirement, again, cannot be met by either one of the two         construction designs mentioned under (a), by itself.

The task of the invention now is to make available a sleeve, particularly a rod sleeve, that meets the entire complex of requirements (a, b).

This task is accomplished, according to the characterizing part of claim 1, in that

-   -   the core hub and the core pin form a one-piece core system that         is provided, however, in two parts with regard to the normal to         the longitudinal axis, whereby both core halves are assembled         with interference fit by means of an insertion-slot system;     -   the core hub, between its two faces, undergoes a tapering with         an angle change, specifically forming a third diameter, whereby         the respective contact surfaces of the core hub and of the outer         sleeve extend in a manner that essentially corresponds to the         elastic layer, as well as     -   the outer sleeve and the elastic layer are provided in two parts         with regard to the normal to the longitudinal axis, whereby both         sleeve halves are assembled with interference fit by means of an         insertion-slot system, whereas both elastic layer halves are         placed at a distance from one another.

According to another variant, the sleeve according to the characterizing part of the independent claim 2, with otherwise the same structural characteristics according to claim 1, is characterized in that the core hub and the core pin are separate components, whereby the core hub is provided in two parts with regard to the normal to the longitudinal axis, whereas the core pin extends continuously and undivided, whereby both hub halves form an interference fit with the core pin within the common hub-pin contact zone.

Practical embodiments of the invention are named in claims 3 to 17.

The invention will now be explained on the basis of exemplary embodiments, making reference to schematic drawings. These show:

FIG. 1 a sleeve in which the core hub and the core pin form a one-piece core system;

FIG. 2 a sleeve in which the core hub and the core pin are separate components, whereby both hub halves abut one another,

FIG. 3 a sleeve in which the core hub and the core pin are separate components, whereby both hub halves are arranged at a distance from one another.

FIG. 1 shows a sleeve 1, comprising a core hub 2, which has two faces 3 with a first and a second diameter D1 and D2, respectively, and a core pin 4 which extends in the direction of the longitudinal axis Y, which pin projects over the two faces of the core hub, forming two connecting journals 5. The core hub and the core pin have cross-sectional areas that are essentially circular.

The core hub 2 and the core pin 4 form a one-piece core system that is provided, however, in two parts with reference to the normal X to the longitudinal axis Y, whereby both core halves A1 and A2 are assembled with interference fit by means of an insertion-slot system 8.

The core hub 2, between its two faces 3, undergoes a tapering with an angle change a, specifically forming a third diameter D3, whereby the respective contact surfaces 9 and 10 of the core hub and of the outer sleeve 6 extend in a manner that essentially corresponds to the elastic layer 7.

The outer sleeve 6 with the total length L and the outside diameter D, as well as the elastic layer 7 with the total length L2 are provided in two parts with regard to the normal X to the longitudinal axis Y, whereby both sleeve halves B1 and B2 are assembled with interference fit by means of an insertion-slot system 11, whereas both elastic layer halves C1 and C2 are placed at a distance L1 from one another.

The elastic layer 7 is structured to be circumferential, in most cases, if necessary in combination with kidneys (DE 199 31 079 A1, FIG. 4a). However, an elastic layer that is provided with separating chamber can also be used (DE 42 08 448 C1, FIG. 2). The elastic layer consists of an elastic material, particularly on the basis of natural rubber (NR), or a thermoplastic elastomer (TPE). A structure as a layer spring is also possible (DE 199 13 777 C1). The thickness S of the elastic layer 7, which is essentially constant, is 2 mm to 30 mm, preferably 10 mm to 20 mm, specifically with reference to the unstressed state. The distance L1 between both elastic layer halves C1 and C2 comprises approximately the entire center hub region with the third diameter D3. Furthermore, the total length L2 of the elastic layer 7, including the distance L1 between both layer halves C1 and C2, is less than the total length L of the outer sleeve 6.

It is practical if the following value ranges apply to the sleeve 1 with regard to D, D1, D2, D3, L, L1, and α:

-   L:D=1:2 to 2:1, preferably 1.5:1 -   D1 or D2:D3=3:1 to 1.5:1, preferably 2.5:1 to 2:1 -   L:L1=3:1 to 10:1, preferably 5:1 to 10:1 -   α=2° to 80°, preferably 30° to 60° (reference point: longitudinal     axis Y)

FIG. 2 shows a sleeve 1′ in which the core hub 2′ and the core pin 4′ are separate components, whereby the core hub is provided in two parts, whereas the core pin extends continuously, whereby both hub halves A3 and A4 form an interference fit with the core pin within the common hub-pin contact zone 12. Furthermore, both hub halves A2 and A4 abut one another (abutment zone 13).

The sleeve 1″ according to FIG. 3 differs from the exemplary embodiment according to FIG. 2 merely in that both hub halves A5 and A6 of the core hub 2″ are arranged at a distance L3 from one another, which is less than the distance L1 between both elastic layer halves C1 and C2. The core pin 4″, which extends continuously, is thicker within its center region, whereby the projection 15 of the thickened part 14 of the pin is the stop 16 for both hub halves A5 and A6, at the same time.

As far as the other design details of the sleeves 1′ and 1″ are concemed, reference is made to the exemplary embodiment according to FIG. 1.

REFERENCE SYMBOL LIST

-   1, 1′, 1″ sleeve (rod sleeve) -   2, 2′, 2″ core hub -   3 faces of the Core hub -   4, 4′, 4″ core pin -   5 connecting journal -   6 sleeve -   7 elastic layer -   8 insertion-slot system of the core -   9 contact surface of the core hub to the elastic layer -   10 contact surface of the outer sleeve to the elastic layer -   11 insertion-slot system of the outer sleeve -   12 hub-pin contact zone -   13 abutment zone -   14 thickened part of pin -   15 projection -   16 stop -   A1, A2 core halves -   A3, A4 hub halves -   A5, A6 hub halves -   B1, B2 sleeve halves -   C1, C2 layer halves -   D diameter of the outer sleeve -   D1 first diameter -   D2 second diameter -   D3 third diameter -   L total length of the outer sleeve -   L1 distance between two layer halves -   L2 total length of the elastic layer -   L3 distance between two hub halves -   S thickness of the elastic layer -   X normal to the longitudinal axis -   Y longitudinal axis -   α angle in the region of the hub tapering 

1-17. (canceled)
 18. A rod sleeve comprising: a) a core, comprising: i) a core hub that has two opposite faces, having a first diameter D1 and a second diameter D2; ii) a core pin which extends in a direction of a longitudinal axis Y, which projects over both faces of said core hub while forming two connecting journals; b) an outer sleeve; c) an elastic layer that is arranged between said core hub and said outer sleeve; wherein said core hub and said core pin are formed as separate components, wherein said core hub is formed in two halves with respect to a normal axis X to said longitudinal axis Y, wherein said core pin extends continuously, and wherein both core halves form an interference fit with said core pin within a common contact zone; wherein said core hub has two opposite faces and is tapered between said two opposite faces with an angle change a relative to said longitudinal axis Y, forming a third diameter D3; wherein said elastic layer is formed in two halves, and said outer sleeve is formed in two halves wherein both sleeve halves are assembled with an interference fit via an insertion slot system, whereas, both of said elastic layer halves are spaced at a distance L1 from each another.
 19. The sleeve as in claim 18, wherein both of said hub halves abut one another.
 20. The rod sleeve as in claim 18, wherein both of said hub halves are arranged at a distance L3 from one another.
 21. The rod sleeve as in claim 20, wherein said core pin, which extends continuously, is thicker within a center region, wherein a projection of said thickened part of said pin is a stop for both of said hub halves, which are arranged at a distance L3 from each other.
 22. The rod sleeve as in claim 21, wherein said distance L3 between both of said hub halves is less than a distance L1 between both of said elastic layer halves.
 23. The rod sleeve as in claim 18, wherein said sleeve consists of an elastomer material.
 24. The rod sleeve as in claim 18, wherein said elastic layer is a layer spring, formed of at least two layers made from an elastomer or thermoplastic elastomer, wherein at least one layer is made from metal or plastic.
 25. The rod sleeve as in claim 24, wherein said elastomer material is formed from natural rubber.
 26. The rod sleeve as in claim 18, wherein a thickness S of said elastic layer is essentially constant.
 27. The rod sleeve as in claim 18, wherein said elastic layer has a thickness that is between 3 mm and 30 mm in an unstressed state.
 28. The rod sleeve as in claim 28, wherein said elastic layer has a thickness that is between 10 mm and 20 mm in an unstressed state.
 29. The rod sleeve as in claim 18, wherein said hub is tapered at an angle α between 2° and 80° with reference to its longitudinal axis Y.
 30. The rod sleeve as in claim 29, wherein said hub is tapered at an angle α between 30° and 60° with reference to its longitudinal axis Y.
 31. The rod sleeve as in claim 18, wherein the distance L1 between both of said elastic layer halves comprises an entire center hub region with a third diameter D3.
 32. The rod sleeve as in claim 18, wherein a ratio of said diameter D1 or D2 to D3 comprises the following value range: D1 or D2:D3=3:1 to 1.5:1.
 33. The rod sleeve as in claim 18, wherein a ratio of said total length of said outer sleeve to a distance L1 between both of said elastic layer halves comprises the following value range: L:L1=3:1 to 10:1.
 34. The rod sleeve as in claim 18, wherein a total length L2 of said elastic layer including said distance L1 between both of said elastic layer halves is less than a total length L of said outer sleeve.
 35. The rod sleeve as in claim 18, wherein a ratio of said total length L and said outside diameter D of said outer sleeve comprises the following value range: L:D=1:2 to 2:1. 